Acting in faith is praying instead of worrying, watching instead of hiding, listening when you want to speak, and, generally, a practice of trust-falling every time there is a significant decision to make. Jeremiah, I believe it was, prayed about everything. I could tell so many stories of relying and acting in faith and even after the bad decisions God used them for a good lesson. You can't outwit or make a mistake so great that God cannot correct it and then use it for good.
Prayer just commits our ways to Him. Faith and prayer doesn't change God's mind - they just put us in alignment with His plan by changing our minds. Sometimes it takes a grand mistake to change our mind though and He'll let us because there is treasure in the lesson more valuable than His simply saying "no". A good Dad will let His kids make their own mistakes from time to time so they can gain their own wisdom. If you catch a child every time he is about to fall he will expect you to catch him when he shouldn't be falling anymore.
We are learning lessons for eternity's sake. We cannot expect God to make life less difficult but learn how to worship Him and adore Him while we are learning things that will make us more useful in the Kingdom to come. If I "say-it-and-claim-it" and things don't go according to my plan then I missed the whole point of faith and may actually lose faith. Faith is not my declaring that God will give me what I asked for but that He is always watching out for us and giving us what we are too afraid to ask for. You know, like patience, perseverance, humility, servitude, love.